Influence of pre-silanized glass microfibers on bond strength and nanoleakage of two dentin-bonding agents

Abstract

Aim: The aim of this study was to evaluate the microtensile bond strength (?TBS) and nanoleakage of two dentin-bonding agents (Adper Single Bond 2 (SB) and Adper Prompt L-Pop (PLP) (3M ESPE), with addition of 10% of pre-silanized glass microfibers. Materials and Methods: Twelve extracted third molars were used, which had the occlusal enamel removed. The modified dentin-bonding agents were applied on the occlusal surface of the teeth, following instructions of the manufacturers. Thus, four groups were obtained: G1 - control SB, G2 - Modified SB, G3 - control PLP and G4 – modified PLP. A 4mm composite restoration was built on the entire area of dentin (Z250-A2 3M ESPE) by incremental technique. The restored teeth were sectioned into sticks (1.2 mm x 1.2 mm 7.0 mm). Two sticks of each group was used for nanoleakage analysis by scanning electron microscope (SEM). The ?TBS test was conducted with a cross-head speed of 0.5 mm/min. Data were statistically analyzed by Student's t test, with a significance level set at 5%. Results: The results showed statistically significant differences between G1 and G2 (G1-11.21 MPa +/- 2.69; G2 - 18.21 MPa +/- 7.31) and G3 and G4 (G3- 6.13 MPa +/- 1.62; G4 -18.95 MPa +/- 7.69). The descriptive analysis of SEM images showed less nanoleakage in G2. Conclusion: It is concluded that the addition of 10% of pre-silanized glass microfibers increased the bond strength to dentin of the adhesive systems used and improved the quality of the hybrid layer for Adper Single Bond 2.